1. Field of the Invention
The invention relates in general to a substrate structure and a manufacturing method thereof, and more particularly to a substrate structure applicable to a flip chip and a manufacturing method thereof.
2. Description of the Related Art
Referring to FIG. 1A, a generally known substrate structure is shown. The generally known substrate structure, such as the substrate structure 100 applicable to flip chip, has a substrate 116, a conductive part 102 and an insulation layer 104. The conductive part 102 is for electrically connecting with a chip (not illustrated) such as a flip chip. A part of the conductive part 102 contacts the insulation layer 104 such as a solder mask. The dry film 106 of FIG. 1A is for defining the range of the conductive part 102, is formed prior to the formation of the conductive part 102 and then is removed after the formation of the conductive part 102 so as to form the substrate structure 100. A mask is used during the formation of the dry film 106 for defining the range of the dry film 106.
The conductive part 102 is composed of a material such as tin-lead alloy different from that of the insulation layer 104. As the coefficient of thermal expansion is different for different materials, a crack C may easily occur to the contact surface P between the conductive part 102 and the dry film 106 so that the conductive part 102 is damaged due to the phenomenon of expansion and contraction during the manufacturing of the substrate structure 100 or when the substrate structure 100 is on work.
Besides, referring to FIG. 1B, the alignment mismatch of a dry film of FIG. 1A is shown. As the mask requires precise alignment match, if the shift in alignment match is too big, shift problem as indicated in FIG. 1B will occur to the dry film 106. Thus, the formation of the conductive part in subsequent process will be affected so that shift problem will occur to the conductive part as well.
Referring to FIG. 1C, another implementation of the generally known substrate structure is shown. The generally known substrate structure 108 has a tin ball 110, an insulation layer 118. As the corner 114 of a hole 112 has a large surface tension, the tin ball 110 of the substrate structure 108 cannot completely fill the corner 114, and the quality of electrical connection of the tin ball 110 will deteriorate.